Seawater carbonate chemistry and photosynthetic response of Emiliania huxleyi (CS-369) to UV radiation and elevated temperature duirng experiments, 2011

• Main Authors: Xu, Kai, Gao, Kunshan, Villafañe, Virginia E, Heibling, E W
• Format: Dataset
• Language: English
• Published: PANGAEA 2011
• Subjects: Biomass/Abundance/Elemental composition; Bottles or small containers/Aquaria (<20 L); Calcification/Dissolution; Chromista; Emiliania huxleyi; EPOCA; EUR-OCEANS; European network of excellence for Ocean Ecosystems Analysis; European Project on Ocean Acidification; Haptophyta; Laboratory experiment; Laboratory strains; Light; Not applicable; OA-ICC; Ocean Acidification International Coordination Centre; Pelagos; Phytoplankton; Primary production/Photosynthesis; Single species; Temperature; Schott; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.770102; https://doi.org/10.1594/PANGAEA.770102

Changes in calcification of coccolithophores may affect their photosynthetic responses to both, ultraviolet radiation (UVR, 280-400 nm) and temperature. We operated semi-continuous cultures of Emiliania huxleyi (strain CS-369) at reduced (0.1 mM, LCa) and ambient (10 mM, HCa) Ca2+ concentrations and, after 148 generations, we exposed cells to six radiation treatments (>280, >295, >305, >320, >350 and >395 nm by using Schott filters) and two temperatures (20 and 25 °C) to examine photosynthesis and calcification responses. Overall, our study demonstrated that: (1) decreased calcification resulted in a down regulation of photoprotective mechanisms (i.e., as estimated via non-photochemical quenching, NPQ), pigments contents and photosynthetic carbon fixation; (2) calcification (C) and photosynthesis (P) (as well as their ratio) have different responses related to UVR with cells grown under the high Ca2+ concentration being more resistant to UVR than those grown under the low Ca2+ level; (3) elevated temperature increased photosynthesis and calcification of E. huxleyi grown at high Ca2+concentrations whereas decreased both processes in low Ca2+ grown cells. Therefore, a decrease in calcification rates in E. huxleyi is expected to decrease photosynthesis rates, resulting in a negative feedback that further reduces calcification.